Coastal Tidal Effects on Industrial Thermal Plumes in Satellite Imagery

Abstract

Coastal tidal effects on thermal plumes are investigated, exploiting remote sensing of two major coastal industrial installations. The installations use sea water as a coolant, which is then released back into coastal environments at a higher-than-ambient temperature, allowing the plume to be delineated from the ambient waters. Satellite-based thermal sensors observing the Earth at spatial resolutions of 90 and 100 m are used. It is possible to identify coastal features and thermal spatial distributions. This paper presents coastal tidal effects on detected plumes for two case studies: an intertidal embayment and open water exposure, both on the coast of the UK. We correlated the behaviours of thermal plumes using remotely sensed high resolution thermal imagery with tidal phases derived from tide gauges. The results show very distinct behaviours for the flood and ebb tides. The detected surface plume location was dependent on flow switching direction for the different types of tide. The detected surface area was dependent on the strength of the currents, with the largest area observed during the strongest currents. Understanding the dispersion of the plume is essential to influence understanding of any potential ecological impacts.